We look at the division of 91422191 by 18 
The aim is to understand the frequency of 18 in 91422191.

Moving on to step 1:
If we divide 9 by 18, we get 0 and a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 9 to get 9.
Take the next digit (1) from the dividend and append it to 9, then repeat: 91 / 18

On to step 2:
If we divide 91 by 18, we get 5 and a remainder of 1.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
The remainder is 1 after subtracting 90 from 91.
Take the next digit (4) from the dividend and append it to 1, then repeat: 14 / 18

Going ahead to step 3:
If we divide 14 by 18, we get 0 and a remainder of 14.
The number 0 becomes the next digit in our result. 
Result so far: 50.0
The remainder is 14 after subtracting 0 from 14.
Take the next digit (2) from the dividend and append it to 14, then repeat: 142 / 18

Moving on to step 4:
If we divide 142 by 18, we get 7 and a remainder of 16.
The number 7 becomes the next digit in our result. 
Result so far: 507.0
Subtract 126 from 142 to get 16.
Include the next digit (2) from the dividend after 16, then repeat: 162 / 18

Going ahead to step 5:
162 divided by 18 is 9 with a remainder of 0.
Put 9 as the next digit of the answer. 
Result so far: 5079.0
If we take 162 away from 162, we end up with 0.
Take the next digit (1) from the dividend and append it to 0, then repeat: 1 / 18

Moving on to step 6:
18 can be fit into 1 0 times, resulting in a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 50790.0
If we subtract 0 from 1, we get 1.
Take the next digit (9) from the dividend and append it to 1, then repeat: 19 / 18

Step 7:
When dividing 19 by 18, we get 1 with a remainder of 1.
The number 1 becomes the next digit in our result. 
Result so far: 507901.0
If we subtract 18 from 19, we get 1.
Bring next digit (1) of the dividend behind the 1 and repeat the process: 11 / 18

Step 8:
If we divide 11 by 18, we get 0 and a remainder of 11.
Put 0 as the next digit of the answer. 
Result so far: 5079010.0
Subtracting 0 from 11 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 9:
If we divide 110 by 18, we get 6 and a remainder of 2.
Use 6 as the next digit of our solution. 
Result so far: 5079010.6
If we take 108 away from 110, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Let's proceed to step 10:
18 can be fit into 20 1 times, resulting in a remainder of 2.
The number 1 becomes the next digit in our result. 
Result so far: 5079010.61
If we take 18 away from 20, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

On to step 11:
If we divide 20 by 18, we get 1 and a remainder of 2.
Put 1 as the next digit of the answer. 
Result so far: 5079010.611
The remainder is 2 after subtracting 18 from 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

The final outcome is 5079010.611, with a leftover of 0.0002.